The use of prefabricated fireplace systems has increased significantly in new construction and also in existing construction where a fireplace was not originally provided. Most prefabricated fireplaces are comprised of concrete and insulated metal structures that are installed in original building construction, or alternatively are freestanding metal shells which are installed in various locations including the corner of an existing room. Known prefab units which are conventionally installed at the time of building construction generally include a metal insulating liner and a built-in, non-removable firebox; the firebox being the actual combustion or fuel-burning chamber. Once the prefab fireplace (usually an open, log burning type) is installed, the unit is essentially permanent. Any attempt to change the type or style of firebox is virtually impossible without a major restructuring or renovation.
Freestanding fireplaces which stand outside the wall in a given area of a room offer slightly more flexibility and can be removed and exchanged for a closed, solid fuel stove. But with these freestanding fireplaces there is no way to obtain the look of a conventional built-in fireplace.
With the advent of improved solid fuel-burning stoves and a trend toward use of these stoves to replace or supplement central heating systems, it has been increasingly desirable to be able to convert a fireplace from an open unit (firebox) to a closed unit, or vice versa. With any built-in fireplace, such modifications are either impossible or quite expensive and not easily accomplished. With some known prefab units, it has been possible to install a wood-burning stove in the fireplace, but no known installations such as this are safety tested and listed by Underwriters Laboratories. Therefore, insurance companies and local building codes are frequently rejecting any prefabricated fireplace modifications which include a fireplace insert. Most prefab fireplaces are too small to receive the stove therein, and since they are an integral part of the prefabricated unit, there is no reasonable way to remove integral parts without damaging the safety components of the whole structure.
It was therefore an objective of the present inventor to develop a prefabricated fireplace unit that could be installed in new or existing construction and which, after installation, could be convertible as desired from an open fireplace to an enclosed stove or vice versa. The present invention accomplishes these and other objectives and is comprised of an insulating cabinet which is installed in the existing or new building framework and which is designed to selectively receive an open or closed firebox. The preferred fireboxes include an open fireplace (for wood or gas logs) and an enclosed solid fuel (wood or coal) burning stove. An exhaust outlet in the outer insulating cabinet is connected to a chimney and to the firebox for exhausting combustion fumes from the building. The fireboxes include damper plates and exhaust outlets which are connected to the corresponding exhaust outlet in the insulating cabinet by an adapter conduit. The firebox exhaust outlet further includes a unique clamping or latching means associated therewith which removably connects the adapter conduit into sealed communication with the exhaust outlet conduit of the insulating cabinet. When it is desired to change fireboxes, the connecting mechanism is disengaged, the adapter conduit lifted, and the firebox is removed from the insulating cabinet and replaced with another. A trim package comprised of a covering frame surrounds the front edges of the top, bottom and side walls of the cabinet housing and abuts the side and top walls of the firebox to conceal the unfinished exposed edges of the two units and make a more attractive assembly.
The preferred enclosed firebox or stove is a wood or coal burning stove constructed in a size to fit within the outer insulating cabinet and designed such that the doors to the stove open into the room from the front.
An optional attached fan mounted between the firebox and the cabinet housing circulates the heated air around the walls of the firebox and back into the room environment.